OBJECTIVE To explore the effects of the nerve growth factor (NGF) on N-methyl-D-asparate receptor 1 (NMDAR 1) after spinal cord injury. METHODS Spinal cord injury of Wistar rats was performed with Allen's method by a 10 gx2.5 cm impact on the posterior T8 spinal cord. NGF was given to the rats of the treatment group via subarachnoid space tube at once, 2, 4, 8, 12 and 24 hours after spinal cord injury, respectively. The expression of NMDAR1 mRNA in spinal cord was detected by in situ hybridization. RESULTS Rare expression sequence of NMDAR1 mRNA was found in rat spinal cord of the normal group. A strong expression sequence of NMDAR1 mRNA was found in rat spinal cord of the normal saline group. The expression of NMDAR1 mRNA in the NGF group was significantly decreased as compared with that in the normal saline group (P=0.01). CONCLUSIONS NGF can relieve damage of injured spinal cord by prohibiting the expression of NMDAR1 mRNA.